Int E0 Fn 001D  - Pcrobots V1.41 - "debug_flag" - Set/clear Markers Next   [g]

   AX = 001Dh
   BX = flag number (0 or 1)
   CX = new value (0 reset, 1 set)

Return: nothing
Program: PCROBOTS is P.D. Smith's adaptation of Tom Poindexter's CROBOTS, in
     which specially-written .COM or .EXE programs form robots battling
     each other in a user-defined arena

Note:  the two flag markers may be used for any purpose, typically for
     debugging to provide a visual display of progress